Showtime's hit series Dexter took inspiration from Jeff Lindsay's award-winning 2004 novel, Darkly Dreaming Dexter, yet the Michael C. Hall-led show made one major change that ensured its success. Over the course of eight seasons and one sequel spin-off, Dexter made its titular protagonist simultaneously repellent and undeniably beguiling, using sly humor to tell his story in an often blackly comic way. Such an approach would not have been possible without one major novel change.

Like Dexter season 1, Darkly Dreaming Dexter (the first of eight Dexter novels) follows blood spatter analyst Dexter Morgan as he leads a double life as a law enforcement employee and vigilante killer. Unlike subsequent Dexter seasons, season 1 actually sticks to the plot of the novel fairly closely. Both stories revolve around an ice truck killer (referred to in the book as the "Tamiami Slasher") who turns out to be Dexter's brother Brian. However, while...